aws lambda如何在S3中存储通过https检索的图像

Question

我正在尝试编写一个lambda脚本，可以从站点中提取图像并将其存储在S3中。我遇到的问题是将什么样的对象作为Body属性传递给S3.putObject方法。在文档here它说它应该是new Buffer('...') || 'STRING_VALUE' || streamObject，但我不知道如何将https响应转换为其中之一。以下是我试过的：

var AWS = require('aws-sdk'); 
var https = require('https'); 
var Readable = require('stream').Readable; 
var s3 = new AWS.S3(); 
var fs = require('fs'); 

var url = 'https://upload.wikimedia.org/wikipedia/commons/thumb/1/1d/AmazonWebservices_Logo.svg/500px-AmazonWebservices_Logo.svg.png'; 

exports.handler = function(event, context) { 
    https.get(url, function(response) { 
    var params = { 
    Bucket: 'example', 
    Key: 'aws-logo.png', 
    Body: response // fs.createReadStream(response); doesn't work, arg should be a path to a file... 
        // just putting response errors out with "Cannot determine length of [object Object]" 
    }; 

    s3.putObject(params, function(err, data) { 
     if (err) { 
     console.error(err, err.stack); 
     } else { 
     console.log(data); 
     } 
    }); 
    }); 
}; 

Answer 1

正如评论中所示，Lambda允许将文件保存在/tmp中。但你并不需要它...

response不包含文件的内容，但是http响应（带有它的状态码和头文件）。

你可以尝试这样的事：

var AWS = require('aws-sdk'); 
var https = require('https'); 
var s3 = new AWS.S3(); 

var url = 'https://upload.wikimedia.org/wikipedia/commons/thumb/1/1d/AmazonWebservices_Logo.svg/500px-AmazonWebservices_Logo.svg.png'; 

exports.handler = function(event, context) { 
    https.get(url, function(res) { 
    var body = ''; 
    res.on('data', function(chunk) { 
     // Agregates chunks 
     body += chunk; 
    }); 
    res.on('end', function() { 
     // Once you received all chunks, send to S3 
     var params = { 
     Bucket: 'example', 
     Key: 'aws-logo.png', 
     Body: body 
     }; 
     s3.putObject(params, function(err, data) { 
     if (err) { 
      console.error(err, err.stack); 
     } else { 
      console.log(data); 
     } 
     }); 
    }); 
    }); 
}; 

Answer 2

试试这个包https://www.npmjs.com/package/request

var request = require('request'); 

exports.handler = function (event, context) { 
    s3.putObject({ 
     Bucket: 'example', 
     Key: 'aws-logo.png', 
     Body: request.get(url, {followRedirect: false}) 
    }, function (err, data) { 
     if (err) console.error(err, err.stack); 
     else console.log(data); 
    }) 
}